System for controlling movements of elevator doors



June 4, 1963 R. A. BURGY 3,092,209

SYSTEM FOR CONTROLLING MOVEMENTS OF ELEVATOR DOORS Filed Sept. '7, 1955 24 o 2, INVENTOR. RA YMOQ/D A. BURGY 2.3 B Jig- E 1% A TORN Y8 rare 'nite In modern elevator installations power operated mechanisms are employed to open doors automatically when cars arrive at hoistway entrances and to close doors before the cars depart. Passengers sometimes attempt to leave or enter cars after the doors have started to close. To prevent injury to passengers in such circumstances elevator door closing mechanisms have been equipped with devices which reverse the movement of the doors and cause them to reopen whenever their leading edges approach or encounter obstructions. Some such devices have electrostatic fields which are affected when the door edges approach persons. Others have yieldable memhers along the leading door edges that act upon mechanical contacts to close or open circuits. An installation may include a projector which directs a ray of light across the doorway to a photocell which acts to affect circuits whenever the light ray is eclipsed.

When a person attempts to go through a doorway after the door has started to close usually it is preferable to cause the door to reopen and after remaining open for a brief interval to repeat its closing movement. If however a person lingers in the path of a door the elevator may he kept out of service while the door repeatedly goes through the cycle of reopening, pausing and starting to close.

The principal object of this invention is to provide a control system for door closing mechanism which functions to reopen a door upon the interposition of an obstacle in its path and to halt the door with its leading edge in contact with or in juxtaposition to such obstacle after the door has gone through a reopening, pausing and starting to close cycle for a predetermined interval.

Another object is to provide a system for controlling the closing movements of doors by means of which doors are held open while persons are in or passing through doorways and are reopened upon contact of the leading edges of the doors with persons or objects during a predetermined interval and are halted upon contact of the leading edges with persons or objects after the expiration of such predetermined interval.

Other objects and various features and advantages of the invention will be apparent upon perusal of the following description as illustrated by the accompanying drawings in which:

FIG. I is a schematic elevational view of an elevator car having door operating mechanism and a sliding door equipped with a yieldable leading edge, a projector being so located as to direct a ray of light across the doorway and a photocell being so located as to receive such ray of light.

FIG. II is an enlarged fragmentary sectional view taken as indicated by the line II-II of FIG. I.

FIG. III is a wiring diagram of circuits employed in the device of my invention.

The following description and the accompanying drawing are descriptive and illustrative of a preferred embodiment of the invention but they are not intended to impose limitations on its scope.

The elevator car illustrated in FIG. I is shown as having a single side opening door 11 though the invention is equally applicable to the control of mechanism for opening and closing multiple doors. The door 11 is hung from rollers 12 and 13 which roll along a track 14 mounted on a superstructure 15 carried by the car 10.

fi dd fidii Patented June 4, 1963 The superstructure 15 supports a three phase induction motor 13 which is connected through a belt 17 to a large pulley 16 on the shafit of which is fixed a sheave 19. One bight of a cable 20 takes over the sheave 19 while another bight thereof takes over an idler sheave 21 and the lower lay of the cable 20 is connected to an arm 22 which projects rigidly upwardly from the door 11.

When the three phase induction motor 18 turns in one direction, e.g. clockwise, the door 11 is moved toward closed position. When the motor 18 turns in the opposite direction the door 11 is moved toward open position.

As illustrated in the wiring diagram of FIG. III the three phase induction motor 18 is supplied with current from three power lines designated L1, L2, and L3. One terminal 23 of the motor 18 is connected directly and permanently to line L1. A second terminal 24 is connectible through contacts 25 to line L2 or alternatively through contacts 26 to line L3. The third terminal 27 of the motor 18 is connectible through contacts 28 to line L2 or alternatively through contacts 29 to line L3.

In order to insure that whenever the second terminal 24 is connected through the contacts 25 to line L2 the third terminal 27 will be connected through the contacts 29 to line L3, the contacts 25 and 29 are tied together to make their respective circuits simultaneously and to break their respective circuits simultaneously. When the terminal 24 is connected through the contacts 25 to the line L2 and the terminal 27 is connected through the contacts 29 to the line L3 the motor 18 will turn in a direction to move the door 11 toward closed position. Likewise in order to insure that whenever the second terminal 24 is connected through the contacts 26 to line L3 the third terminal 27 will be connected through the contacts 28 to line L2 the contacts 26 and 28 are tied together to make their respective circuits simultaneously and to break their respective circuits simultaneously. When the terminal 24 is connected through the contacts 26 to line L3 and the terminal 27 is connected through the contacts 28 to line L2 the motor 18 will turn in a direction to move the door 11 toward open position.

When the contacts 25 and 29, 26 and 28 all are open themotor 18 will stop and the door 11 will stand still wherever it is when the motor stops.

The contacts 25 and 29 are shown schematically as tied together by a rod which extends through a door closing relay 31 that is energized by a circuit that ordinarily is broken at contacts 32. The circuit energizing the door closing relay 31 ordinarily can be made by the contacts 32 when a start relay 33 is energized. The circuit energizing the start relay 33 ordinarily is made by contacts 34 when the car operating system is conditioned to start the car. The start relay circuit making contacts 34- are indicated schematically as push button contacts. The interlock that prevents the car from starting before the door is closed is not part of the instant invention and being well known it is not illustrated or described herein.

The contacts 26 and 28 which make and break the circuits that cause the motor 18 to turn in a direction to open the door 11 are schematically shown as tied together by a rod which extends to a door opening relay 35 that is energized by a circuit that is made only when the car is at, or within a few inches of a landing at which time the circuit is made at contacts such as are schematically indicated at 36. Moreover the circuit which energizes the door opening relay 35 is always broken at contacts 37 whenever the door closing relay 31 is energized. Hence the circuits that cause the motor 18 to turn in a direction to open the door are always broken whenever the circuits are made that cause the motor to turn in a direction to close the door.

The circuit that energizes the door opening relay 35 3 is broken at a door open limit switch 33 whenever the door is completely open. The circuit that energizes the door closing relay 31 is broken at a door close limit switch 39 whenever the door is completely closed.

The circuits so far described are shown in the condition that exists with the door standing open at a landing. In order to keep the door standing open for a brief interval to permit passengers to enter or leave the car after the door has opened, the circuit that energizes the start relay 33 is broken by energization of a short interval time relay 40 whose energizing circuit is broken at contacts 41 when the car stops at a landing. The short interval time relay 40 holds contacts 42 out of engagement for a predetermined short interval, e.g. one second, after the car stops, so that the start relay 33 is never energized until that short interval elapses. When the start relay 33 is energized it separates contacts 43 and thus deenergizes the door opening relay 35.

Energization of the start relay 33 moves contacts 44 into engagement which makes a by-pass hold-in circuit that keeps the start relay energized even if the short interval time relay is reenergized and the original start relay energizing circuit is broken.

A source of light 45 is arranged to project a ray of light across the doorway to impinge upon a photocell 46 (see FIG. I). The photocell 46 is wired in series with contacts 47 of a switch which is opened whenever a yieldable or sensitive edge 48 is against a person or other obstruction in the doorway. Also wired in series with the photocell 46 and sensitive edge contacts L7 are contacts of a push button t9. Eclipse of the beam of light to the photocell 46, touching the sensitive edge 48, or pressing the push button 49 breaks the main circuit of a normally energized safety relay i).

Deenergization of the safety relay 50 breaks, at contacts 51, the circuit of the door closing relay 31, breaks, at contacts 52, the by-pass hold-in circuit of the start relay 33, and makes at contacts 53 a circuit which energizes the short interval time relay 4-0. Deenergization of the safety relay 5% thus causes the door 11 to reopen if it has started to close or keeps it immobile if it has not started to close.

In day to day operation the circuit of the safety relay 50 will seldom be broken by touching the sensitive edge 48 unless the door 11 has partially closed. The circuit will be broken however time after time, while the door is wide open, by repeated eclipse of the beam of light as persons pass through the doorway. Because of the delaying action of the short interval time relay 4%) the door will not start to close until, e.g. one second after light is readmitted to the photocell 46.

Since the door 11 will not start to close until after light is readmitted to the photocell 46 a person who knowingly or unknowingly lingers in the doorway and thereby eclipses the light beam might hold up the opera tion of the elevator car indefinitely. To obviate this undesirable possibility the circuit that energizes the safety relay 50 may be shunted around the photocell 46. The shunt is effected by contacts 55 which are moved into engagement by a motor operated timer 56 the motor of which is energized by a circuit that is made at the contacts 34 whenever the car operating system is conditioned to start the car. After a predetermined long interval, e.g. fifteen seconds, while the circuit through the photocell 46 continues to be broken, the circuit through the contacts 55 is made thus reenergizing the safety relay 5%. Thereupon the door 11 moves toward closed position until either the circuit that energizes the safety relay 55 is broken at the contacts 47 by engagement of the sensitive edge 48 with a person or object or the circuit that energizes the door closing relay 31 is broken at the limit switch 39. In either case the door ceases to move but does not reopen.

The motor operated timer 56 also pulls in contacts 59 which are wired in parallel with the contacts 52.

Hence if the circuit that energizes the safety relay is broken at the contacts 47 by engagement of the sensitive edge 48 with a person or object while the timer 56 has pulled in the contacts 59 the start relay 33 will remain energized and the circuit that energizes the door closing relay 31 will remain broken and the door will remain in engagement with the person or object, resuming its closing movement when the obstruction is withdrawn.

The hoisting mechanism and the electric circuits controlling the hoisting mechanism and controlled by the movements and positions of the car It) in its hoistway are not shown. Hoisting mechanism and devices such as operate contacts 41 to break the circuit that energizes the short interval time relay 40 when the car stops at a landing and operate contacts 60 so that when the car is standing at a landing a circuit can be made to energize the start relay 33, e.g. one second after the circuit which energizes the short interval time relay 40 is broken at the contacts 41, are well known and no feature of any such hoisting mechanism and circuits which operate contacts 41 and 60 enters into the instant invention.

The instant invention is susceptible to variation without departing from the spirit and scope of the subjoined claims.

Having described the invent-ion, I claim:

1. A system for controlling movements of elevator doors comprising, in combination, a motor, means, including a door closing relay, for causing said motor to turn in a door closing direction, means, including a door opening relay, for causing said motor to turn in a door opening direction, a start relay which when energized acts to condition circuits for simultaneously energizing said door closing relay and deenergizing said door opening relay, a safety relay which when energized acts to condition circuits for energizing said door closing relay and said start relay, said start relay and said safety relay acting when deenergized to decondition such respective circuits, a door adapted to open or close, a doorway, door operating mechanism driven by said motor, a sensitive edge on said door, a sensitive edge switch operated thereby, a photocell, means casting a beam of light across said doorway to impinge upon said photocell, said sensitive edge switch and said photocell being wired in series in a circuit for energizing said safety relay, whereby said safety relay is deenergized either by interference of an obstruction with said sensitive edge or by darkening of said photocell by an object in said doorway, means, including a short interval time relay, for momentarily delaying reenergization of said start relay upon reenergization of said safety relay, and means, including a timer, for establishing circuits for keeping said start relay energized after a predetermined period enduring for a plurality of seconds.

2. A system for controlling movements of elevator doors comprising, in combination, a motor, means, including a door closing relay, for causing said motor to turn in a door closing direction, means, including a door opening relay, for causing said motor to turn in a door opening direction, a safety relay which when energized acts to condition circuits for energizing said door closmg relay and deenergizing said door opening relay, said safety relay acting when deenergized to decondition such circuits, a door adapted to open or close, a doorway, door operating mechanism driven by said motor, a sensitive edge on said door, a sensitive edge switch operated thereby, a photocell, means casting a beam of light across said doorway to impinge upon said photocell, said sensitive edge switch and said photocell being wired 1111 series in a circuit for energizing said safety relay, r y aId safety relay is deenergized either by interference of an obstruction with said sensitive edge or by darkening of said photocell by an object in said door- Way, and means, including a timer, for conditioning cir-.

ouits for keeping said door opening relay deenergized and for shunting current around said photocell after a predetermined period enduring for a plurality of seconds.

References Cited in the file of this patent 6 Lubkin Nov. 27, 1934 Wechsler Oct. 29, 1935 Bruns et al. Apr. 14, 1953 Santini Mar. 19, 1957 Eames Sept. 17, 1957 Eames Aug. 18, 1959 

1. A SYSTEM FOR CONTROLLING MOVEMENTS OF ELEVATOR DOORS COMPRISING, IN COMBINATION, A MOTOR, MEANS, INCLUDING A DOOR CLOSING RELAY, FOR CAUSING SAID MOTOR TO TURN IN A DOOR CLOSING DIRECTION, MEANS, INCLUDING A DOOR OPENING RELAY, FOR CAUSING SAID MOTOR TO TURN IN A DOOR OPENING DIRECTION, A START RELAY WHICH WHEN ENERGIZED ACTS TO CONDITION CIRCUITS FOR SIMULTANEOUSLY ENERGIZING SAID DOOR CLOSING RELAY AND DEENERGIZING SAID DOOR OPENING RELAY, A SAFETY RELAY WHICH WHEN ENERGIZED ACTS TO CONDITION CIRCUITS FOR ENERGIZING SAID DOOR CLOSING RELAY AND SAID START RELAY, SAID START RELAY AND SAID SAFETY RELAY ACTING WHEN DEENERGIZED TO DECONDITION SUCH RESPECTIVE CIRCUITS, A DOOR ADAPTED TO OPEN OR CLOSE, A DOORWAY, DOOR OPERATING MECHANISM DRIVEN BY SAID MOTOR, A SENSITIVE EDGE ON SAID DOOR, A SENSITIVE EDGE SWITCH OPERATED THEREBY, A PHOTOCELL, MEANS CASTING A BEAM OF LIGHT ACROSS SAID DOORWAY TO IMPINGE UPON SAID PHOTOCELL, SAID SENSITIVE EDGE SWITCH AND SAID PHOTOCELL BEING WIRED IN SERIES IN A CIRCUIT FOR ENERGIZING SAID SAFETY RELAY, WHEREBY SAID SAFETY RELAY IS DEENERGIZED EITHER BY INTERFERENCE OF AN OBSTRUCTION WITH SAID SENSITIVE EDGE OR BY DARKENING OF SAID PHOTOCELL BY AN OBJECT IN SAID DOORWAY, MEANS, INCLUDING A SHORT INTERVAL TIME RELAY, FOR MOMENTARILY DELAYING REENERIZATION OF SAID START RELAY UPON REENERGIZATION OF SAID SAFETY RELAY, AND MEANS, INCLUDING A TIMER, FOR ESTABLISHING CIRCUITS FOR KEEPING SAID START RELAY ENERGIZED AFTER A PREDETERMINED PERIOD ENDURING FOR A PLURALITY OF SECONDS. 